Large and highly textured regions, referred to as macrozones or microtextured regions, with sizes up to several orders of magnitude larger than those of the individual grains, are found in dual-phase titanium alloys as a consequence of the manufacturing process route. These macrozones have been shown to play a critical role in the failure of titanium alloys, specifically being linked to crack initiation and propagation during cyclic loading. Modeling microstructures containing macrozones using continuum-level formulations to describe the elastic–plastic deformation at the grain scale, i.e., crystal plasticity, poses computational challenges due to the large size of the macrozones, which in turn prevents the use of modeling approaches to understand their deformation behavior. In this work, a crystal plasticity-based modeling approach is implemented to model macrozones in Ti–6Al–4V. Further, to overcome the large computational expense associated with modeling microstructures containing macrozones, a modeling strategy is introduced based on a crystal plasticity description for the macrozone with a reduced-order model for the surrounding aggregate combining anisotropic elasticity and J2 plasticity, based on crystal plasticity-based training data. This modeling approach provides a grain-level description of deformation within macrozones using elastic–plastic continuum simulations, which has often been overlooked. Finally, the reduced-order model is used to investigate the strain localization within the microstructure and the effect of varying the misorientation tolerance on the localization of plastic strain within the macrozones.

中文翻译：

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在钛合金中的微织构区域中模拟应变局部化：Ti–6Al–4V

由于制造工艺路线的原因，在双相钛合金中发现了较大且高度织构化的区域，称为宏观区域或微织构区域，其尺寸比单个晶粒的尺寸大几个数量级。这些大区域已被证明在钛合金的失效中起着至关重要的作用，特别是与循环载荷期间的裂纹萌生和扩展有关。使用连续水平的公式对包含宏观区域的微观结构进行建模，以描述晶粒尺度上的弹塑性变形（即晶体可塑性），由于宏观区域的尺寸较大，因此在计算上存在挑战，这反过来又阻止了使用建模方法来了解它们的大小。变形行为。在这项工作中 实施了基于晶体可塑性的建模方法来对Ti-6Al-4V中的大区域进行建模。此外，为了克服与包含大区域的微观结构建模相关的大量计算开销，基于大区域的晶体可塑性描述引入了建模策略，并基于晶体可塑性将各向异性弹性和J2可塑性结合了周围聚集体的降阶模型基于训练的数据。这种建模方法使用弹塑性连续谱模拟提供了宏观区域内变形的颗粒级描述，而这种模拟常常被忽略。最后，使用降阶模型研究微观结构内的应变局部化以及改变取向错误容忍度对大区内塑性应变局部化的影响。